1. Field of the Invention
The present invention relates to telecommunication networks, and more specifically to a method and apparatus for reducing overhead when setting up multiple virtual circuits between two network devices using signaling protocols.
2. Related Art
Virtual circuits are often provided between network devices. A virtual circuit generally defines a path (including intermediate devices and transmission paths) traversed by data packets from one network device to the other. The network devices at either end of the virtual circuit are generally referred to as end systems.
Signaling protocols are often used to set up and terminate (manage, in general) virtual circuits as is well known in the relevant arts. Overhead in terms of both bandwidth usage and processing overhead exists when setting up virtual circuits using signaling messages (often sent using multiple packets).
The bandwidth usage is due to the transfer of signaling messages (in the form of packets) as a part of the signaling task. The processing overhead is present on the intermediate devices and the end systems. The processing overhead may be of particular concern when the packets (containing signaling messages) need to be parsed by the systems, as described below with reference to ATM (asynchronous transfer mode) environments.
As is well known, the signaling related messages of ATM environments contain information elements. Each information element specifies parameters (e.g., quality of service) related to the virtual circuit being managed. Each device in the path of the virtual circuit typically needs to examine and potentially act upon the information elements to appropriately support the virtual circuit.
Accordingly, the signaling messages transferred during set up and termination of virtual circuits may cause at least some level of overhead on each of the devices in the virtual circuit path. The overhead could be unacceptably high if a large number of virtual circuits (e.g., switched virtual circuits) are being set up and terminated. In other words, the devices may not scale to support a large number of virtual circuits.
Therefore, what is needed is a method and apparatus which reduces overhead when setting up multiple virtual circuits between two network devices using signaling protocols.